Abstract

Background

Most randomised clinical trials (RCTs) testing a new health service do not allow a
run-in period of consolidation before evaluating the new approach. Consequently, health
professionals involved may feel insufficiently familiar or confident, or that new
processes or systems that are integral to the service are insufficiently embedded
in routine care prior to definitive evaluation in a RCT. This study aimed to determine
the optimal run-in period for a new physiotherapy-led telephone assessment and treatment
service known as PhysioDirect and whether a run-in was needed prior to evaluating
outcomes in an RCT.

Methods

The PhysioDirect trial assessed whether PhysioDirect was as effective as usual care.
Prior to the main trial, a run-in of up to 12 weeks was permitted to facilitate physiotherapists
to become confident in delivering the new service. Outcomes collected from the run-in
and main trial were length of telephone calls within the PhysioDirect service and
patients’ physical function (SF-36v2 questionnaire) and Measure Yourself Medical Outcome
Profile v2 collected at baseline and six months. Joinpoint regression determined how
long it had taken call times to stabilise. Analysis of covariance determined whether
patients’ physical function at six months changed from the run-in to the main trial.

Results

Mean PhysioDirect call times (minutes) were higher in the run-in (31 (SD: 12.6)) than
in the main trial (25 (SD: 11.6)). Each physiotherapist needed to answer 42 (95% CI:
20,56) calls for their mean call time to stabilise at 25 minutes per call; this took
a minimum of seven weeks. For patients’ physical function, PhysioDirect was equally
clinically effective as usual care during both the run-in (0.17 (95% CI: -0.91,1.24))
and main trial (-0.01 (95% CI: -0.80,0.79)).

Conclusions

A run-in was not needed in a large trial testing PhysioDirect services in terms of
patient outcomes. A learning curve was evident in the process measure of telephone
call length. This decreased during the run-in and stabilised prior to commencement
of the main trial. Future trials should build in a run-in if it is anticipated that
learning would have an effect on patient outcome.